Much of the rail industry is self-regulated with respect to equipment that is required on board. Currently, many trains include event recorders that measure all of the operator inputs to the vehicle. The United States Federal Railroad Administration (FRA) defines an event recorder as a device, designed to resist tampering, that monitors and records data on train speed, direction of motion, time, distance, throttle position, brake applications and operations (including train brake, independent brake, and, if so equipped, dynamic brake applications and operations) and, where the locomotive is so equipped, cab signal aspect(s), over the most recent 48 hours of operation of the electrical system of the locomotive on which it is installed. The event recorders are similar to “black boxes” in airplanes. Most on-board event recorders record all of this information into (solid state) memory. Data from the solid-state memory can be uploaded if it must be analysed or reviewed.
Recording technologies for use in rail applications must be incredibly rugged. Environmental problems that must be dealt with include heat, vibration, humidity, electrical disturbances, etc. Solid-state memory can be used for such applications to mitigate some of these effects. However, there is a need to store more and more information in event recorders, including data types that take up a lot of memory. For example, providing 48 hours of video data recording can generally take about 60 gigabytes of storage. Solid-state memory is presently 70 times the cost of hard disk storage; therefore, there is a commercial advantage if hard drives could be used.
Typical hard drive technology can only operate between 5 degrees and 55 degrees Celsius. Train temperatures can be well outside this temperature range. Typical hard drive technology also does not perform well if subjected to vibration, and will fail when exposed to high levels of humidity.
It is, therefore, desirable to provide a recording (storage) system that is suitable for use in the rail industry, or in other environments where a vehicle's operating temperature (and possibly vibration levels, and humidity levels) exceed the specified hard drive operating range.